Motherboard Spec Question and CPU Price Question

I am looking at ASUS or Gigabyte in the 4 slots of DDR4 2133 or higher flavor.
I was looking at this wikipedia page on motherboards.
https://en.wikipedia.org/wiki/LGA_1151
B150 looks like an attractive price point for me. We dont use many USB ports.
What does "PCH PCI Express configuration" mean?
[TABLE="class: wikitable"]
[TR]
[TD]B150 - 8 × 3.0[/TD]
[TD]Q150 - 10 × 3.0[/TD]
[TD]
H170 - 16 × 3.0[/TD]
[TD="colspan: 2"]

Q170 & Z170 - 20 × 3.0[/TD]
[/TR]
[/TABLE]


Some motherboard specification sheets state (O.C.) meaning its overclocked. So I need to OC the ram in order to get that speed. Other spec sheets just state it without (O.C.) statement.
Gigabyte B150M-D3H GSM w/ DDR3 1600, 7.1 Audio, Gigabit LAN, 2-Way CrossFireX, HDMI, DVI-D, VGA at Memory Express

4x DDR3 DIMM sockets for up to 32GB RAM (4x 8GB)
- Supports standard DDR3-1866 (OC) / 1600 / 1333MHz Non ECC UDIMMS

Click to expand...

How long will it take for the i5-6400 (listed below) to get to around the $125 mark?
I was figuring to start with the G4400 then buy the i5-6400 later.

CPU
Pentium Processor G4400, 3.3GHz w/ 3MB Cache $85 2 core 2 threads
Core™ i5-6400 Processor, 2.7GHz w/ 6MB Cache $255 4 core 4 threads

PCI express is simply a connection type for using cards most notably graphics cards. It is the successor to pci cards. PCH refers to the chipset. You don't really need to worry about that. I can tell you this overclocking is never a requirement and some (but not all) manufacturers will consider your warranty void if you do so. If done incorrectly it can result in instability and even cause early hardware failure. As for price, we cannot know what the future will bring. It will likely go down but we can't know how long that will take.

OK Thanks a lot. I was looking at new mobo's cuz I thought maybe my old one bit the dust. But I got it going again, thanks to a technician and $50 for an hours T/S'ing. The new GTX650 GPU was too new and too powerful for my old mobo. It lasted a year. The slot still works and the GPU still works the tech said. I cant play World of Tanks anymore at 12FPS, unlike my 40FPS I had before with the GTX650. Will get some more years out of this old computer after all. Get to keep the old MS Office software suite and desktop windows mail feature.

While I was looking at the mobo's I am fascinated by the wide variations, features and prices. It just boggles my mind. Besides my "slightly more then basic" RAM and CPU knowledge everything else is above my head. PCI-e 3.0, PCE-e x16, bus lanes, two x8 blah blah blah. I am beginning to think with all the extra's I just need to pick what style of monitor connector I want to use, how many monitors, RAM type, CPU chipset/speed/cache, graphics card whether it be tethered aka Xfire/Crossfire /2-way crossfire/CrossfireX or singular, and slots. Lots to learn.